chore(deps): update dependency rss to v0.3.1

Author: renovate[bot]

Gemfile.lock

@@ -86,10 +86,11 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redcarpet (3.6.0)
-    rexml (3.2.6)
+    rexml (3.2.9)
+      strscan
     rouge (1.11.1)
     rr (3.1.1)
-    rss (0.3.0)
+    rss (0.3.1)
       rexml
     ruby2_keywords (0.0.5)
     sass (3.7.4)
@@ -122,6 +123,7 @@ GEM
       unicode-display_width (>= 1.5, < 3.0)
       unicode_utils (~> 1.4)
     strings-ansi (0.2.0)
+    strscan (1.0.3)
     terminal-table (3.0.2)
       unicode-display_width (>= 1.1.1, < 3)
     terser (1.2.3)